Lundborg, Petter - Institute for the Study of Labor (IZA) - 2008
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Keywords: health production, education, schooling, twins, siblings, returns to education,
ability bias … that may otherwise bias the schooling coe� cient.
To the best of my knowledge, this is the �rst study using a twin … bias compared to OLS estimates.2 As a major can-
didate for such within-twin-pair di�erences, Bound and Solon (1999 …